Electrode and terminal structure for non-impact printer

ABSTRACT

Printing means for high-speed non-impact printers of the type having character-shaped, pulsed electrodes. Mutually facing electrode and terminal sheets have insulating bases upon the nonfacing surfaces of which are disposed character electrodes and corresponding connection terminals. The respective electrodes and terminals are mutually connected by conductor leads extending through the sheets. Surrounding portions of the non-facing surfaces and portions of the facing surfaces extend about the electrodes and terminals and are electrically conductive and connectable to circuit means for the purpose of shielding and suppressing arcs between electrodes or between terminals, or between electrodes and terminals.

UIlitEd States 1 1 Koch et al.

11] 3,733,613 1 May 15, 1973 1541 ELECTRODE AND TERMINAL STRUCTURE FORNON-IMPACT PRINTER [75] Inventors: Paul L. Koch, Saugus; James C.

Maxwell, Winchester, both of Mass.

[73] Assignee: The Carters Ink Company, Cambridge, Mass.

[22] Filed: Aug. 16, 1971 [2]] Appl. No.: 172,067

52 U.S. Cl. .....346/74 E, l0l/DIG. 13 51 Int. Cl. .0010 15/06, 001d15/20 58 Field of Search ..346/74 E, 74 ES, 346/74 CH, 74 s, 14 SB, 74SC; 178/30;

1o1/oio. 13

[56] References Cited UNITED STATES PATENTS 3,550,153 12/1970- Haebetleet al ..346/74 E 7/1969 Stegenga ..l78/30 4/1969 Young ..346/74 ESPrimary ExaminerBernard Konick Assistant Examiner-Robert S. Tupper Att0rney- Herbert W. Kenway et al.

571 ABSTRACT Printing means for high-speed non-impact printers of thetype having character-shaped, pulsed electrodes. Mutually facingelectrode and terminal sheets have insulating bases upon the nonfacingsurfaces of which are disposed character electrodes and correspondingconnection terminals. The respective electrodes and terminals aremutually connected by conductor leads extending'through the sheets.Surrounding portions of the non-facingsurfaces and portions of thefacing surfaces extend about the electrodes and terminals and areelectrically conductive and connectable to circuit means for the purposeof shielding and suppressing arcs between electrodes or betweenterminals, or between electrodes and terminals.

10 Claims, 4 Drawing Figures FIG. 3

Patented May 15, 1973 3,733,613

2 Sheets-Sheet 1 g Q (\1 v o co m ,5 co 3 m3 1 5 N p /x f w J, 1- 10 gFIG.I

FIG. 2

INVENTORS PAUL L. K H JAMES C. XWELL ATTORNEYS 2 Sheets-Sheet 2INVENTORS PAUL L. KOCH JAMES C. MAXWELL ATTORNEYS FIG. 4

1 ELECTRODE AND TERMINAL STRUCTURE on Non-[rumor PRINTER BRIEF SUMMARYOF THE INVENTION This invention relates generally to printers effectiveby means of pulsed, character-shaped electrical fields in the region ofthe printing surface. Examples of such printers are disclosed in the US.Pat. to Robert W. Haeberle et al. US. Pat. No. 3,550,153, dated Dec. 22,1970. This patent describes printing by means of a pulse of shortduration creating a shaped electrical field between a donor sheet and aclosely adjacent recipient sheet. The surface of the donor sheet facingthe recipient sheet carries electrically conductive particles of aprinting material or pigment dispersed in or on a high resistancemedium. The electrical field causes a current flow that leaves asufficient charge on the printing material to cause it to move to therecipient sheet under the influence of the shaped electrical field. Theelectrical pulses are typically of very brief duration and are FIG. 4 isan exploded view showing the structures of i the electrode and terminalsheets.

applied between a first, character-shaped electrode and a second orground electrode so disposed that the donor and recipient sheets arewithin-the shaped electrical field. The amplitude of the applied pulsesdepends on a number of factors including the construction andorientation of the sheets and the presence or absence of interveninginsulator sheets, but typical values may range from several hundreds ofvolts to more than 1,000 volts.

In typical alphanumeric printers it is desirable and usually necessaryto locate the character-shaped electrodes in close physicalrelationship. This presents a problem of possible arcing between theelectrodes whereby defective printing as well as spurious printing ofundesired characters may result. An object of this invention is toprovide printing means adapted to prevent such arcing, whereby the fullpulse for each :desired character to be printed is delivered only to theappropriate electrode.

Another object is to provide printing means having a compact, simplifiedand economically fabricated structure.

This invention achieves the foregoing objects, as well as other objectshereinafter appearing, by the provision of a pair of mutually facingsheets respectively having upon their nonfacing surfaces thecharacter-shaped electrodes and the corresponding terminals forconnecting the electrodes with the pulse circuits of the printer. Thesheets are electrically connected by a number of leads that extendthrough insulating substrates on the sheets and respectively connecteach electrode with its corresponding terminal. Portions of the sheetsadjacent to and surrounding the electrodes and terminals are groundedfor arc suppression and shielding purposes.

Other features of the invention will be evident from the followingdescription of a preferred embodiment thereof.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a view in plan illustratingthe principal parts of a high speed non-impact, pulsed electrode printerembodying this invention.

FIG. 2 is a front elevation taken on line 2--2 of FIG. 1.

FIG. 3 is a side elevation in Section taken on line 3-3 of FIG. 2.

DETAILED DESCRIPTION Referring to the drawing, the printing meansaccording to this invention comprises an electrode sheet 12 and aterminal sheet 14 in closely adjacent, facing rela-..

selection control circuits for the printer. These circuits may takevarious forms within the purview of one skilled in this art, as will beevident from the description below.

A composite paper web 20 extends from a supply roll 22 'over a curvedface of the electrode sheet 12 to a take-up roll 24. These rolls aredriven in a conventional manner, preferably at a constant speed bearinga'predetermined relationship to controls for the character selectionimpulses passing through the several wires 19. A flexible metal band 28isreceived over rolls 30 and held under tension by a spring 32, therebyurging the web 20 with alight pressure against the surface of the sheet12. Preferably, the band 28 is grounded to the frame of the printer, asillustrated.

The paper web 20 may be of any suitable type adapted to form a visibleor latent image of selected characters when subjected to an electricalfield formed by the application of brief electrical pulses between theelectrode sheet'lZ and the band 28. While the invention is not primarilyconcerned with the particular structureof the web 20, an example isillustrated in the drawing for application of the invention to themethods described in the above-identified Haeberle patent. This webcomprises a donor web 34 and a recipient web 36. The donor web 34 maycomprise a substrate fabric of cloth material, paper or plastic film,which either comprises or has coated upon it a high resistivity mediumupon which printing particles 38-are dispersed. These particles aremobile and electrically conductive pigment particles which, in thepresence of a brief electrical field pulse, are physically transferredfrom the donor sheet to the facing surface of the recipient web 36 asdescribed in said patent. The web 36 may be any suitable paper uponwhich the particles may be thus de-v posited to form a visible image.The shape of this image depends upon the shape of the applied electricalfield which is defined by the shapes of character electrodes on thesheet 12 as hereinafter described. While the webs 34 and 36 are shown inFIG. 3 as being somewhat separated, in practice they are preferably infacing contact, being held in contact by a light pressure appliedby theband 28 or by other means that will permit easy and rapid separation ofthe webs 34 and 36 after the image transfer has occurred.

Details of the structure of the electrode and terminal sheets 12 and 14are illustrated in FIGS. 3 and 4. Preferably, the sheets both have thesame basic structure consisting of insulating bases or substrates 40 and42 of high dielectric material such'as nylon or the equivalent, thesesubstrates being initially coated with a layer of copper or othermetallic conductor. Both surfaces of the sheet 14 are so coated, and thenon-facing surface of the sheet 12 is thus coated. The copper isselectively etched from the surfaces to leave the residual conductivepatterns as hereinafter more fully described.

The side of the electrode sheet 12 that faces the composite web 20 has alarge electrically Conductive marginal surface 44 definingacentraletched region 46 that is non-conductive except for a pattern ofelectri' cally conductive character-shaped electrodes 48, preferablyarranged in a line containingall of the available alphanumericcharacters and any other desired punctuation marks, patterns, designsincluding logotypes, ligatures and symbols to be printed in desiredsequences to form a text,'music or other composition, or a formula orany other visible collocation of the availablecharacters. The oppositeface of the sheet l2is preferablyuncoated whereby the insulating surfaceof the base 40 is exposed throughout the area of the sheet 12 facing thesheet 14.

The electrode sheet 14 has a side 50 facing the sheet 12, this sidehaving a substantial electrically conductive marginal surface 52defining an etched, 'nonv conductive central region 54 generally alignedwith the region 46 on the sheet 12, and also defining nonconductivemargins 55. The sheet 14 also has 'a side 56, this side having asubstantial electrically conductive marginal surface 58 and a pluralityof mutually spaced electrically conductive strips 60. These strips, likeall of the other electrically conductive surfaces on the sheets Thestrips 60 preferably have eye shaped central end portions 62 andterminal end portions 64. The central portions 62. are located inopposed relationship'to the non-conducting, uncoated central region 54on the opposite side of the sheet 14, and the end portions 64 arepreferably located near the side periphery of the sheet 14 in opposedrelationship to the non-conductive margins 55. Substantial spacingexists between the respective ends 64 to facilitate connection withexternal con? trol circuits. For making such connections, holes 66 arepreferably drilled through the sheet 14 in the centers of the eye-shapedends 62 and 64 of the strips 60, and connection wires such as 67 aresoldered to the end terminals 64 and extend to the pulse circuitsassociated with the wires 19.

An electrical lead wire 68 passes through a drill hole in the base 40 ofthe sheet 12 (FIG. 3) and is soldered or otherwise electricallyconnected with the underside of each character electrode 48. This wirepasses through a corresponding hole 66 in the sheet 14 and is solderedas at 70 to a central end portion 62 of a corresponding strip 60. Thusthe opposite terminal end portion 64 of this strip comprises terminalmeans by which the character may be connected through the wire 67 withcircuits associated with the leads 19 of FIG. 1.

The above-described structure also provides means for shielding therespective character electrodes 48 and strips 60 from one another andfrom spurious externally-generated electrical fields. To this end, thoseelectrically conductive surface portions of the sheets 12 and 14 thatare not electrically connected with the electrodes 48 and strips 60 asabove described are connected together and suitably grounded to thecontrol circuit. This may be accomplished in various ways, for exampleby machine screws or other fasteners passing through holes 72 that alsoserve for alignment andsupport of the sheets. Thus the surface portions44, 52 and 58 are electrically connected together and grounded.

The shielding between each adjacent pair of strips 60 is furtherincreased by the provision of integral spaced extensions 74 of thesurface 58, as shown in FIG. 4. By this means the surface portion 58electrically isolates the respective strips 60. Preferably, the strips60 are often arranged so that alternate strips extend in oppositedirections from the central portion of the sheet 14 as shown, therebyproviding space for the extensions 74 as above described.

In a corresponding manner, longitudinally-extending electricallyconductive lateral portions 76 of the surface 52 between thenon-conductive areas 54 and 55 provide isolation between circuit wiressuch as 67 and the leads 68 extending between the sheets 12 and 14.

Printing means comprising sheets 12 and 14 are readily fabricated in themanner hereinabove described, and a given printer may be provided with alarge number of pairs of sheets comprising various typographical stylesand combinations of selectable printing characters 48. Etchingtechniques employing photographic resists, which are well known in theart,

Other variants of the above-described structures will be apparent to oneskilled. in this art, in ordertoconform to selected printerconfigurations and printing circuit requirements.

We claimz" l. Prin ting means having, in combination,

an electrode sheet comprising an insulating base and A a plurality ofcharacter-shaped electrodes arranged in a pattern on a surface thereof,said surface having a conductive portion substantially surrounding theregion including saidpattem without electricallycontacting saidelectrodes,

a terminal sheet having a surface facing the other surface of saidelectrode sheet and comprising an insulating base and a plurality ofmutually spaced electrically conductive strips on the non-facing surfacethereof, each strip corresponding to an electrode on the first sheet andhaving a first end and a second end, the first ends of said strips beingaligned with said pattern and the second ends having terminal means,

and a lead extending through the bases of said sheets and electricallyconnecting each said electrode with the first end of a correspondingstrip.

2. Printing means according to claim 1, wherein the electrodes areetched metallic coatings.

3. Printing means according to claim 1, wherein the electrodes andstrips are etched metallic coatings.

4. Printing means having, in combination,

an electrode sheet comprising an insulating base and a plurality ofcharacter-shaped electrodes arranged in a pattern on a surface thereof,

a terminal sheet having a surface facing the other surface of saidelectrode sheet and comprising an insulating base, a plurality ofmutually spaced electrically conductive strips on the non-facing surfacethereof and mutually connected conductive portions extending betweensaid strips, each strip corresponding to an electrode on the first sheetand 1 having a first end and a second end, the first ends of said stripsbeing aligned with said pattern and the second ends having terminalmeans, and a lead extending through the bases of said sheets andelectrically connecting each said electrode with the first end of acorresponding strip. 5. Printing means according to claim 4, wherein theelectrodes are etched metallic coatings.

6. Printing means according to claim 4, wherein the electrodes andstrips are etched metallic coatings.

7. Printing means according to claim 4, wherein said 6 strips aregenerally parallel and said conductive portions are elongate and extendbetween said strips.

8. Printing means according to claim 7, wherein said facing surface ofsaid terminal sheet has a conductive portion extending transversely ofsaid strips between and in nonoverlapping relation to the first andsecond ends thereof.

9. Printing means according to claim 7, wherein said jacent stripsextend on alternate sides of said pattern. l t

1. Printing means having, in combination, an electrode sheet comprisingan insulating base and a plurality of character-shaped electrodesarranged in a pattern on a surface thereof, said surface having aconductive portion substantially surrounding the region including saidpattern without electrically contacting said electrodes, a terminalsheet having a surface facing the other surface of said electrode sheetand comprising an insulating base and a plurality of mutually spacedelectrically conductive strips on the non-facing surface thereof, eachstrip corresponding to an electrode on the first sheet and having afirst end and a second end, the first ends of said strips being alignedwith said pattern and the second ends having terminal means, and a leadextending through the bases of said sheets and electrically connectingeach said electrode with the first end of a corresponding strip. 2.Printing means according to claim 1, wherein the electrodes are etchedmetallic coatings.
 3. Printing means according to claim 1, wherein theelectrodes and strips are etched metallic coatings.
 4. Printing meanshaving, in combination, an electrode sheet comprising an insulating baseand a plurality of character-shaped electrodes arranged in a pattern ona surface thereof, a terminal sheet having a surface facing the othersurface of said electrode sheet and comprising an insulating base, aplurality of mutually spaced electrically conductive strips on thenon-facing surface thereof and mutually connected conductive portionsextending between said strips, each strip corresponding to an electrodeon the first sheet and having a first end and a second end, the firstends of said strips being aligned with said pattern and the second endshaving terminal means, and a lead extending through the bases of saidsheets and electrically connecting each said electrode with the firstend of a corresponding strip.
 5. Printing means according to claim 4,wherein the electrodes are etched metallic coatings.
 6. Printing meansaccording to claim 4, wherein the electrodes and strips are etchedmetallic coatings.
 7. Printing means according to claim 4, wherein saidstrips are generally parallel and said conductive portions are elongateand extend between said strips.
 8. Printing means according to claim 7,wherein said facing surface of said terminal sheet has a conductiveportion extending transversely of said strips between and innonoverlapping relation to the first and second ends thereof. 9.Printing means according to claim 7, wherein said pattern issubstantially linear and said strips extend transversely thereof. 10.Printing means according to claim 9, wherein adjacent strips extend onalternate sides of said pattern.